**7. Conclusions**

ICSI has permitted NOA men, who were previously unable, to conceive biological children. Studies have demonstrated varying rates of clinical (pregnancy and live birth rates) outcomes likely due to a heterogenous population of men with NOA included in these studies, and future studies would benefit from etiology-specific outcome reporting. Understanding clinical outcomes after ICSI is important for prognostic information and counseling of these NOA men and their partners prior to undergoing invasive surgical procedures. Further work is needed to delineate the molecular mechanisms and genetic defects that underlie this severe reproductive phenotype.

**Author Contributions:** Conceptualization P.N.S.; writing—C.K., N.P., and P.N.S.; review and editing— C.K., N.P., and P.N.S.; supervision P.N.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** C.K. and N.P. are supported in part by the Frederick J. and Theresa Dow Wallace Fund of the New York Community Trust.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors have no conflict of interest to declare.
